Biodiversity is the variety of life in a given range. Today, the world is under tremendous threat of unprecedented loss of biodiversity. Issues like global warming, environmental pollution, recurrent natural calamities and human population rise are of major concern for scientists all over the world. The second edition of the book covers a complete range of the topics pertaining to the subject such as meaning of biodiversity, its history, importance of species diversity, systematics, determination of status of bioresources, pattern of distribution of global species, genetic diversity and ecosystem diversity. It also elaborates on various drivers that lead to biodiversity loss and its impact on global climate. Moreover, the topics on biopiracy, related laws and policies, and the importance of indigenous knowledge of several communities are also described in the text. The use of biotechnology-based methods and various measures to preserve natural resources and conserve biodiversity is the highlight of the text. Moreover, the book provides a detailed account of the conservation measures of biodiversity, especially those implemented by the government. This book is primarily designed for the undergraduate and postgraduate students of Environmental Science, Zoology and Botany. Besides, it will also be useful for postgraduate diploma or other professional courses in Environmental Science and also for the researchers. NEW TO THE SECOND EDITION ‘Project Tiger’ and ‘Project Elephant’ are introduced in the chapter on Conservation Practice. Various sections have been revised and updated through- out the book. A few figures have been added and many others have been replaced for better illustration.